Such a railway traction vehicle is known and shown in FIG. 3 of WO 2014/126480 A1. This known railway traction vehicle includes a carriage 50 and a locomotive 10 hauling carriage 50. Carriage 50 may be equipped with a hydrogen driven fuel cell 53 that generates electricity inter alia for the locomotive's electric traction motors 15. Hydrogen storage tanks 52 may be installed on the roof of carriage 50 that supply fuel cell 53 with hydrogen.
Since the hydrogen is stored in the storage tanks 52 at high pressure, the storage tanks 52 must be sturdy. Accordingly, they are very heavy. The presence of the heavy storage tanks 52 on the carriage's roof substantially increases the railway traction vehicle's fuel consumption. Furthermore, this large weight leads to an unfavourable load distribution on the carriage's axles.
Document EP 2 423 067 A1 discloses in its FIGS. 10 to 12 a diesel-electric locomotive 100 including two heavier inner operating modules 122, 123 and two lighter outer operating modules 119, 121. The operating modules may be electrically connected via a collecting rail 160. This document does however not deal with the storage of fuel gas on a railway traction vehicle.